Green zones can help reduce noise levels by 40%

Green zones can help reduce noise levels by 40%
Bhama Devi Ravi | TNN

Chennai: Ever wondered why localities with more trees seem more peaceful than ones that barely have green patches? The answer is: Trees are nature’s very own noise cancellation mechanism.The presence of even a small patch of vegetation can reduce noise levels considerably, say experts. “Acting as shields, trees reduce the intensity of the sound waves considerably,” says Professor D Narasimhan of Madras Christian College. Depending upon the type of tree, the density of foliage and the distance between buildings, noise levels can cut down upto 40% of the noise generated in a typical urban landscape. “One of the measures for reducing noise pollution is to plant trees on arterial roads. The additional benefit is that they would also reduce other pollutants like particulate matter” says Narasimhan. However, the challenge is to plant the correct species of trees, say forest department officials and activists.
As per a study conducted last week by the geomatics centre of the Tamil Nadu forest department, Chennai Metropolitan Area (CMA) stretching to 178 sq km, has a forest cover of 16.81 sq km, which means the city enjoys nearly 9% green cover. But development works in the recent past have resulted in felling of trees in many localities, leading to a public interest litigation a little over a year ago. The Madras High Court has now passed a directive stating that for every tree that is felled, 50 saplings have to be planted. However, there are no clear guidelines on what kinds of tress are best suited to a specific area. “The problem with the city is that everything is an ad-hoc solution. Selection of trees, planning on where to plant them and management of the same are crucial areas that need to be addressed. Trees like gulmohars must be avoided,” says Narasihman.
Some of the species recommended by the botanist include Crataeva Adansonii (Mavalingam), the Calophyllum Inophyllum (Punnai), the Hibiscus Tiliaceus (Nirparathi), the Pamburus Missionis (Kurundhu, Kaattu Narinji) and Eerkolli. Many of these can grow between 5 m to 15 m high.
“Tree planting drives are a big success, with everyone from the government to schools, colleges and NGOs, turning sensitive to the need for green cover” says Shoba Menon, of ‘Nizhal’ an NGO. Narasimhan agrees but states that there is neither planning nor coordination between the various entities. “We need a nodal agency, a group which will supervise and give a broad guideline with regard to tree planting and tree maintenance,” he said.
bhama.devi@timesgroup.com